Extended Data Table 1.

Measured distances between residues labeled with FRET pairs

	Inter-residue distance *
Structure used	D435–E945	S355–S867	S867–N1054
Apo (4CMP)	21 Å	79 Å	6 Å
sgRNA-bound (4ZT0)	78 Å	81 Å	7 Å
sgRNA/DNA-bound (4OO8 mol A)	77 Å †	61 Å	34 Å ‡
sgRNA/DNA-bound (4UN3)	83 Å	59 Å	28 Å §
sgRNA/DNA-bound, HNH docked state ||		21 Å	57 Å §

^*Distances were measured between Cα atoms of the indicated residues, except where indicated, for the denoted structures (PDB IDs in parentheses).

^†E945 is disordered in the structure; an average of measured distances to T941 and I950 is reported.

^‡N1054 is disordered in the structure; an average of measured distances to T1048 and I1063 is reported.

^§N1054 is disordered in the structure; an average of measured distances to I1050 and K1059 is reported.

^||The docked state for the HNH domain was generated using PDB IDs 4UN3 and 2QNC.